Feeling less clear about famous residence (6,3)
I believe the answer is:
number ten
'famous residence' is the definition.
(10 Downing Street)
'feeling less clear about' is the wordplay.
'feeling less' becomes 'number' (I've seen this before).
'clear' becomes 'net' (as in net profit).
'about' says the letters should be written in reverse.
'net' in reverse letter order is 'ten'.
'number'+'ten'='NUMBER TEN'
(Other definitions for number ten that I've seen before include "as part of political address" , "centre of political power" , "PM's residence" , "Figure on the British PM's door" , "centre of government" .)